Check out these tips and videos on How to Find Your 1 Rep max for powerlifting.
Warmup with mobility exercises that will be similar to your barbell exercise. If you are going to perform barbell squats then use air squats as your warmup.
low-rep warm-up sets with smaller weight increases to turn on your nervous system, keep fatigue at bay and successfully crush a new one-rep max.
A one rep max attempt may look like this
350×1 (new personal record)
Questions from our SGPT Athletes:
Question: Coach; how can I find out my 1 rep max with a calculator?
Answer: Check out this article from NASM